1. Field of the Invention
The present invention relates to a cable reel to be mounted on a steering device of a vehicle such as, for example, an automobile.
2. Description of Related Art
For convenience of explanation, a prior art cable reel will be described with reference to FIGS. 6 through 8. FIG. 6 is an exploded perspective view of a prior art cable reel. FIG. 7 is a bottom view of a prior art inner case, illustrating the inner case attached to a movable member. FIG. 8 is a top view of the prior art inner case, illustrating the inner case attached to a stationary member.
A conventional cable reel to be mounted on a steering device of an automobile, as shown in FIG. 6, has a stationary member 1 adapted to be secured to a steering column and a movable member 2 adapted to be secured to a steering wheel. Both members 1 and 2 are rotatably coupled to each other. A flat cable 3 is contained in an annular space defined between the stationary member 1 and the movable member 2 in a coiled manner.
An end of the flat cable 3 is connected to an end of a bus bar 5 fixed in an inner case 4 while the other end of the flat cable 3 is connected to an end of a bus bar 8 fixed in an inner case 7. The other ends of the bus bars 5 and 8 are connected to lead wires 6 and 9, respectively.
The first inner case 4 is accommodated in a first inner case containing portion 2a in the movable member 2 while the second inner case 7 is accommodated in a second inner case containing portion 1a in the stationary member 1.
However, the flat cable 3 is caught by a guide rib 2b when the first inner case 4, connected to the end of the flat cable 3, is inserted into the first inner case containing portion 2a in the movable member 2 by sliding the inner case 4 upwardly in the portion 2a, as shown in FIG. 7, since the guide rib 2b extends arcuately from an end of a cable outlet portion of the case containing portion 2a. This results in lowering the efficiency of the assembly operation and in damaging the flat cable 3.
Similarly, the flat cable 3 is caught by a guide rib 1b when the second inner case 7, connected to the other end of the flat cable 3 is inserted into the second inner case containing portion 1a in the stationary member 1 by sliding the inner case 7 downwardly in the portion 1a, as shown in FIG. 8, since the guide rib 1b extends arcuately from an end of a cable outlet portion of the case containing portion 1a. This results in lowering the efficiency of the assembly operation and in damaging the flat cable 3.
An object of the present invention is to provide a cable reel that can improve efficiency of an assembly operation and prevent a flat cable from being damaged when inner cases connected to opposite ends of the flat cable are attached to a housing of the cable reel.
In order to overcome the above problems, an aspect of the present invention is directed to provide a cable reel wherein a movable member forming an inner cylinder is rotatably coupled to a stationary member forming an outer cylinder, a flat cable is accommodated in an annular space defined by the stationary and movable members, first and second inner cases that accommodate bus bars connected to conductive elements in the flat cable are attached to longitudinal opposite ends of the flat cable, the bus bars are drawn out from the first and second inner cases, and the first and second inner cases are fixed in first and second inner case containing portions provided in the movable and stationary members, respectively. The cable reel is characterized in that: a first protection rib extends from an end surface of a cable outlet portion in the first inner case fixed in the first inner case containing portion in the movable member; and the first protection rib includes an arcuate inner peripheral wall and an arcuate outer peripheral wall in the first inner case, the arcuate outer and inner peripheral walls being opposed to each other to define a cable-threading path between them.
In the above construction, the flat cable is not caught by the guide rib of the first inner case containing portion and the flat cable can be prevented from being damaged, since the first protection rib extending from the end surface of the first inner case protects the opposite side surfaces of the flat cable, when the first inner case is inserted into the first inner case containing portion of the movable member.
Since the inner and outer peripheral walls of the first protection rib, that serves to protect opposite side surfaces of the flat cable, are formed into an arcuate configuration, an outer shape of the first inner case including the first protection rib is substantially the same as an inner shape of the first inner case containing portion including the guide rib, thereby smoothing and improving an inserting operation of the first inner case into the first inner case containing portion.
In addition, since the flat cable extending from the first inner case is held in an arcuate shape, the flat cable can be led in a rotating direction continuously and can be wound smoothly into the annular space.
A distal end of the first protection rib is preferably disposed on a tangential line on an outer peripheral surface of the inner cylinder of the movable member. That is, the distal end of the first protection rib coincides with a portion of the flat cable drawn out from the first inner case. The distal end of the first protection rib of the first inner case is disposed on a tangential line on an outer peripheral surface of the inner cylinder of the movable member. Consequently, it is possible to prevent the flat cable from being curved excessively toward the outer cylinder when the flat cable is introduced into the annular space.
A second protection rib extends from an end surface of a cable outlet portion in the second inner case fixed in the second inner case containing portion in the stationary member. The second protection rib includes an arcuate inner peripheral wall and an arcuate outer peripheral wall in the second inner case. The arcuate inner and outer peripheral walls are opposed to each other to define a cable-threading path between them.
In the above construction, as stated in the first inner case, the flat cable is not caught by the guide rib of the second inner case containing portion, since the second protection rib extending from the end surface of the second inner case protects the opposite side surfaces of the flat cable, when the second inner case is inserted into the second inner case containing portion of the stationary member, thereby preventing the flat cable from being damaged and thereby smoothing and improving an inserting operation of the second inner case into the second inner case containing portion.
A further aspect of the present invention provides a cable reel in which a movable member forming an inner cylinder is rotatably coupled to a stationary member forming an outer cylinder and a flat cable is positioned in an annular space defined by the stationary and movable members, first and second inner cases that accommodate bus bars connected to conductive elements in the flat cable are attached to longitudinal opposite ends of the flat cable, the bus bars extend from the first and second inner cases, and the first and second inner cases are fixed in first and second inner case containing portions provided in the movable and stationary members, respectively, is provided in which one of the first and second inner cases includes a first protection rib extending from an end surface of a cable outlet portion of one of the first and second inner cases, and wherein the first protection rib includes an arcuate portion defining a cable threading path.
According to another aspect of the present invention, a distal end of the first protection rib may be positioned on a tangential line on an outer peripheral surface of the inner cylinder of the movable member. Further, a distal end of the second protection rib may be positioned on a tangential line on an outer peripheral surface of the outer cylinder of the stationary member.
According to a further aspect of the present invention, the first protection rib may extend from an end surface of a cable outlet portion in the first inner case fixed in the first inner case containing portion in the movable member, and the cable reel may further include a second protection rib extending from an end surface of a cable outlet portion of the second inner case fixed in the second inner case containing portion in the stationary member, and the second protection rib may include an arcuate portion defining a second cable threading path. Further, the first inner case containing portion may include a first arcuate guide rib, and the arcuate portion of the first protection rib may be configured to engage the first arcuate guide rib, and the second inner case containing portion may include a second arcuate guide rib, and the arcuate portion of the second protection rib is configured to engage the second arcuate guide rib. Further, the first protection rib may include an inner arcuate peripheral wall and an outer arcuate peripheral wall, the inner and outer arcuate peripheral walls of the first protection rib being opposed to each other to define the cable threading path therebetween, the first inner case containing portion includes a first arcuate guide rib, and the inner and outer arcuate peripheral walls of the first protection rib may be configured to engage the first arcuate guide rib, and the second inner case containing portion may include a second arcuate guide rib, and the inner and outer arcuate peripheral walls of the second protection rib may be configured to engage the second arcuate guide rib.
In a further aspect of the present invention, the first protection rib may include an inner arcuate peripheral wall and an outer arcuate peripheral wall, the inner and outer arcuate peripheral walls being opposed to each other and defining the cable threading path therebetween. Further, the first protection rib may extend from an end surface of a cable outlet portion in the first inner case fixed in the first inner case containing portion provided in the movable member. The first protection rib may extend from an end surface of a cable outlet portion in the second inner case fixed in the second inner case containing portion provided in the stationary member, and the second inner case containing portion may include an arcuate guide rib, and the arcuate portion of the first protection rib is configured to engage the arcuate guide rib.
According to a further aspect of the present invention, the first inner case containing portion may include an arcuate guide rib, and the arcuate portion of the first protection rib may be configured to engage the arcuate guide rib. Further, the inner and outer arcuate peripheral walls may extend from an end surface of a cable outlet portion in the first inner case fixed in the first inner case containing portion provided in the movable member. Further, the inner and outer arcuate peripheral walls may extend from an end surface of a cable outlet portion in the second inner case fixed in the second inner case containing portion in the stationary member, and the second inner case containing portion may include an arcuate guide rib, and the inner and outer arcuate peripheral walls are configured to engage the arcuate guide rib.
In a further aspect of the present invention, the second protection rib may include an inner arcuate peripheral wall and an outer arcuate peripheral wall, the inner and outer arcuate peripheral walls of the second protection rib being opposed to each other to define the second cable threading path therebetween.